Compilare: user.cpp: In function ‘void build_matrix()’: user.cpp:62:13: warning: unused variable ‘idx’ [-Wunused-variable] int idx=1; ^ user.cpp: In function ‘void get_level_line_column(int&, int&, int&, int)’: user.cpp:90:13: warning: unused variable ‘s3’ [-Wunused-variable] int s3=ord-s2; ^ user.cpp: In function ‘int main()’: user.cpp:137:9: warning: unused variable ‘lvl’ [-Wunused-variable] int lvl, line, column; ^ user.cpp:137:14: warning: unused variable ‘line’ [-Wunused-variable] int lvl, line, column; ^ user.cpp:137:20: warning: unused variable ‘column’ [-Wunused-variable] int lvl, line, column; ^ user.cpp: In function ‘int minn(int, int, int, int, int&, int&)’: user.cpp:45:5: warning: control reaches end of non-void function [-Wreturn-type] } ^